Edgun R3 .22: Shot String, Air Efficiency, & Trigger
This will be a long post, sorry about that. Ran into the dive shop to fill up the scuba tank yesterday. The shop owner put on a pressure gauge to show me how much the tank was filled, because I was “hinting” at him that I could only fill the gun to 180 bars (~2610 psi) last time with a full tank. The tank was indeed filled to the maximum pressure around 3100 psi in this new fill. Interestingly, again, I only could fill the gun up to ~180 bars based on the gun gauge; but the gauge in the fill adaptor showed 3050 psi (~210 bars). It seems that the pressure of my Edgun was somewhat under measured by 440 psi or 30 bars. 🙄
I tested a shot-string using Combro Chronograph, which is a very small and handy chronograph installed at the end of the muzzle area. The starting pressure was 180 bar (based on Edgun gauge) and JSB Heavy (18.1 grains) was used. The first shot was low in speed (878 ft/sec), but the subsequent 35 shots were consistent with average 916.5±4.5 ft/sec (minimum 910 ft/sec and maximum 926 ft/sec). The regulator came off around 130 bars (I think) because of a little rise in speed for several shots and then the speed dropped to around 840 ft/sec for about 13 shots in parallel with pressure drop. The POI (at 30 yards) started to drop slightly (~0.2”) at shot #37 (or the regulator was off at this point?) The POI didn’t further drop until pressure went below 105 bars. I got 35 good shots consuming ~800 psi (from 180 bar to 125 bar) from a 289-cc air tube with average 33.8 foot-pound muzzle energy, which is about 13.1 bar-cc/ft-lb efficiency of air usage. If using Zoco’s data – green-line shot string, 220 bar to 130 bar for 57 shots, ~32.5 fpe (http://talonairgun.com/forum/viewtopic.php?t=19488&postdays=0&postorder=asc&start=520), I got the number 14 bar-cc/ft-lb efficiency.
Based on the data from a shot-string of Royale 400 (without regulator; average 868 fps with 37 fps extreme spread) (http://www.network54.com/Forum/79537/thread/1318702313/FX+Royale+400+.22+-+90+shot+string+with+chart-target), which consumed 0.94 bar/shot (220 to 135 bars for 90 shots) with ~30.3 fpe from a 400-cc bottle, the air efficiency is 12.4 bar-cc/ft-lb. Using another shot-string (http://airgunadvice.net/viewtopic.php?t=12183), from 220 bars to 179 bars with 36 shots (average 954 fps with 28 fps spread) at ~36.6 fpe, I got the same number (12.4 bar-cc/ft-lb) for air efficiency. Using the data from the FX Royale 400 review video of Ted in Youtube, average 33.53 fpe and 20 fps extreme spread with high power, I got 11.1 bar-cc/ft-lb efficiency. If the medium power is used (884 fps with 31.4 fpe and 13 fps extreme spread), the efficiency will be higher at 9.6 bar-cc/ft-lb. It seems Royale is a little bit better than Matador R3 (standard length) in air efficiency without much sacrificing speed variation in the un-regulator gun.
I think Edgun can be optimized by adjusting the combination of regulator and power to reach max efficiency, but it will need a lot of trial. Or this is already at the optimal condition when Ed designed and set up the gun. What do you think?
p.s
I also installed a Harris bipod BRM-S model 6”-9” in late afternoon, and ran a few shots under high-gust wind (>20 miles/hr) before dark. It seems to improve the unstable sitting of the gun and increase the shooting accuracy. 😛 Will test more tomorrow if weather is good.
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Endo and Mike, I have a couple of ideas.
The HST adjusting screw can be hard to turn if you have tightened the small locking screw in too far. Doing that can mess the threads up on the HST adjuster and make it hard to turn in or out. I took a 12 mm nut and turned it down on a lathe. You could do the same thing with a file or grinder. I no longer use the stock locking screw. I still use needle nose pliers to loosen the lock nut and turn the HST adjuster.
I think that you guys are trying to adjust the HST down too far in an effort to lower your speeds. I don’t think that you now have enough HST to consistently open the air valve fully each fill.
Endo, from the looks of your shot strings, I think that you need to adjust your regulator down about 1/3 turn. I have adjusted all 3 on my Matadors and they all give a 3-4 fps shot to shot variation with a max difference of 10-12 fps spread for the fill. They don’t have a different speed from fill to fill.
When I adjust the regulator, I find that the first full fill will have a different speed than the next fill. It seems to me that the regulator doesn’t lock in until the second fill. I think that it has to be adjusted, the air tube repressurized and then shot down below the regs new set point before it will take the “set”.
I have a Combro also and I found that it wasn’t very repeatable. I got more consistent results from my Shooting Chrony Beta. I also found that I needed to be sure that I was shooting thru the exact same spot on the Chrony or the readings would be off.
For serious regulator adjustments, I came up with this. I know that each shot string is going to go thru the same spot.
HOOT: here is the gauge that I got from McMaster Carr. It is rated 1.5% accurate for the full range. These types of gauges have the best accuracy at ½ of the max pressure. McMaster Carr has gauges that have .5% accuracy but, they cost big bucks!
Endo,
I have the same issue with my gun (.22 R3) where as the regulator changes the fps with each fill up. As you have stated with a variance of 15 -20 fps, sometimes higher sometimes lower. I have over 2500 shots through my gun and would think everything to be settled in by now. I don’t understand it either then again maybe it’s this way with everyone I haven’t a clue. As to adjusting the HS and as suggested by Mark, make sure you have backed out the locking screw. In my case I too have to use pliers due to the set screw had been tighten too much prior to my receiving gun. Be careful, as stated by ED, do not over tighten that set screw or it will burger up the treads thus causing the issue you seem to be experiencing. You seem to be getting accurate groups. Enjoy you EDgun!
Endo,you are loosening the set screw that holds the HST adj. Should
not be that hard to turn.I`m still getting good results with Ballistol
Tried the Edgun pellets in my Marauder LW and got a couple sub .25″
groups.They work good in the Edgun also.Will compare w/jsb when
weather permits. regards,mark
I have a gauge that is certified to be no more than 2% off on it’s reading. Using it, I fill to 3100 psi and the R3’s gauge shows just a little under 200 bar.
My Dear Your Goatship…
Where did you get this super accurate gauge?
Is it on your gun or your filler?
Inquiring minds want to know…my phone has been ringing off the hook. Please update us so I can get some sleep!
Kindest regards,
Uncle H 😯 😯 T
In the past 2-3 weeks, I have been fiddling around with hammer string tension (HST) to see if I can get the speed of R3 I want. I have to say, it is hard to adjust the HST screw. I have to use a pair of pliers to turn the screw. I turned the HST ¼-turn out from the stock setting to reduce the speed from 930 fps to around 910 fps. However, in next day or two, the speed can increase to ~920 or drop to ~890 fps. So, I keep adjusting the screw in and out many times trying to get the speed I want, very frustrating. My experience is that the gun seems to “lock into” different speeds each fill and the mean speed varies 10-15 fps. And the variation of extreme spread within each complete string (or within the same fill) is also around that values. For example, the HST ¼-turn out from the stock setting generates mean speed about 910 fps in one fill and can generates 920 fps in another fill, and then 895 fps in another fill in different days with extreme spread around 10-15 fps. Does the regulator setting, in addition to HST, also contribute to the speed variation, I mean the mean speed in each fill?
Also got some chances shooting at 51-yard targets. Shooting with lubed (KryTech, Finishing Line) and unlubed JSB Heavy. It appears that the unlubed ones (average about 0.41” ctc) edge out the lubed ones (about 0.47”). Among those 8 groups in each category, the best group is 0.23” unlubed and the second best is 0.26” lubed. The worst group was around .55” (unlubed) and 0.72” (lubed). There were always one or two “flyers” (or just shooter’s problem) to spoil the entire group. Next time will try Ballistol since Mark got good results from it.
Got the Gray White tank from Joe B. three weeks ago. Filled the gun to 3000 psi (tank gauge) and the gun gauge reads 195 bars. So, the gun gauge reading is about 12 bars lower than that from the tank gauge. I found the gun was shooting ~935 fps (JSB Heavy 18.1 grains) last week or two, which was increased from ~926 fps measured last time. I don’t know why the speed was creeping up with time. So, I reduced the hammer spring tension by ¼ turn-out the tension rod and the speed was reduced to ~907 fps (averaged from 9 shots). I didn’t have enough pellets to shoot a complete string at that time. It took 8 days to receive pellets from PA via FedEx-USPS (the delivery time is inversely related to the shipping $). Did a chronograph yesterday and here is the string.
Turning hammer spring tension down by ¼ turn from stock setting:
The average speed is 918.2±4.6 fps (shot #1 to #58) with 33.9±0.3 ft-lb energy, starting pressure was 195 bars (gun gauge). The speed is increased just by 10 days. Don’t know why.:roll: The target distance is 30 yards, POI is consistent until pressure was dropped to 92 bars (shot #73). Air efficiency is 12.08 cc-bar/ft-lb for the first 60 shots, which is improved from the 13 cc-bar/ft-lb calculated last time, but the extreme spread is doubled now. I have about 60 regulated shots and a total of 72 useful shots in this fill. I might be able to squeeze out more if spring tension were further reduced. The more I shoot, the more I like the gun.
I don’t know why the speed is creeping up with time. Is there anyone having the same experience? Is this normal?
Both gauges from Joe B’s seems to be pretty on with my R3’s gauge.
I have a gauge that is certified to be no more than 2% off on it’s reading. Using it, I fill to 3100 psi and the R3’s gauge shows just a little under 200 bar.
OG, don’t tell us you have such a gauge without telling us where you got it and how much it cost and how it fits and how you found out about it and how long it took to get it and what it looks like and was it from Europe or Englandia, or sum such!
Then post some pictures.
Kindest regards,
Uncle H 😯 T
PS: or are you just telling us that YOUR EDgun gauge is really really accurate and your 2% gauge is on your filler upper thingee?
The gauge just screws into the front plug. Be sure that all of the air is out of the gun before you remove it!
I have a gauge that is certified to be no more than 2% off on it’s reading. Using it, I fill to 3100 psi and the R3’s gauge shows just a little under 200 bar.
http://www.luchtbuks.com/luchtbuks/index.php?page=winkel.php&detail=1104
Wow, that is an expensive chronograph. I think I will stick with my combro, which makes very consistent measurements and does not need to mess around the lighting conditions.
The accuracy of pressure gauge in the gun might not be critical if I know the behavior of the gun. I know that the speed of my gun will start dropping at 120 bars and the POI will drop if pressure is below 100 bars, and I will have a total of 65 good shots if the tube is filled to 200 bars based on the gauge of the gun. The pressure reading from the gun is just a way of telling me what I can predict from the gun, although the gauge is not accurate. Hopefully, my logic is correct. Of course, I like to see the accuracy of the pressure gauge matches with the shooting capability of the gun. But this is rather minor. I admire Ed’s perfectionism of making accurate gun… So, just a quick question, how easy/difficulty is it to change the gun gauge? 🙂
Regards,
Endo
It has been my experience that some pressure gauges can be adjusted to “zero”, some…not all!
I’ve never looked at the back of my Edgun gauge, perhaps someone else has, or perhaps Ed can tell us if it is adjustable.
All air gauges are off by a few psi one way or another, but yours sounds a bit further out than that. Let’s see if someone knows if the Edgun gauge can be adjusted up or down.
If it isn’t, and it poses a problem for you, perhaps Tony has one laying around that he might exchange yours for a few bucks???
Regards,
Hoot
Ask Zoco, he has like 5 chrono’s and all five give different readings 🙂
So it could be your 1st readings are the same as these readings, but your chrono is not reading correct…….
The best chrony is this one:
http://www.luchtbuks.com/luchtbuks/index.php?page=winkel.php&detail=1104
Costs a lot but with maybe a group by if you have other shooters in your neighborhood?
that is great looking string!
Shoot some more. adjust down to 900-910 and enjoy!
I shot another string this afternoon. The gun was filled to 192 bars based on gun gauge. 5-shot as a group with a total of 70 shots.
The average velocity was 926.7±2.3 ft/sec with 9 ft/sec extreme spread. The speed was increased from my last string 916 ft/sec but the extreme spread was reduced almost by half. Nothing was adjusted from last time except trigger weight was reduced based on Tedd’s method.
Anyway, this time I had 45 regulated shots (926.7±2.3 ft/sec). From 120 bars, the speed started to drop, which is identical to that found in last time, but the speed was not suddenly drop this time. The following 15 shots did not have a significant drop in POI, although the speed was gradually reduced to 875 ft/sec. Shot #61 to #65 got a slight drop in POI by 3/16” (starting 100 bars) and the last 5 shots with average ½” drop in POI. This is consistent with my last string showing significant POI drop at ~105 bars. The end pressure was 87 bars.
I don’t know why the speed in regulated shots was increased by 10 ft/sec from last time. I guess the gun has not settled down yet. Once she is tamed, I will definitely reduce the speed to around 890-900 ft/sec as Tedd and F&D have suggested. If I filled the pressure to 200 bars, I will have 50 regulated shots and the total useful shots will be 65. I am happy with the results. The accuracy at different sets of speed will be tested. Stay tuned. 🙂
Tedd, hope you get R3 .22 soon and I eager to see what you can get from the BSA barrel.
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The HST adjusting screw can be hard to turn if you have tightened the small locking screw in too far. Doing that can mess the threads up on the HST adjuster and make it hard to turn in or out. I took a 12 mm nut and turned it down on a lathe. You could do the same thing with a file or grinder. I no longer use the stock locking screw. I still use needle nose pliers to loosen the lock nut and turn the HST adjuster.
I think that you guys are trying to adjust the HST down too far in an effort to lower your speeds. I don’t think that you now have enough HST to consistently open the air valve fully each fill.
Endo, from the looks of your shot strings, I think that you need to adjust your regulator down about 1/3 turn. I have adjusted all 3 on my Matadors and they all give a 3-4 fps shot to shot variation with a max difference of 10-12 fps spread for the fill. They don’t have a different speed from fill to fill.
When I adjust the regulator, I find that the first full fill will have a different speed than the next fill. It seems to me that the regulator doesn’t lock in until the second fill. I think that it has to be adjusted, the air tube repressurized and then shot down below the regs new set point before it will take the “set”.
I have a Combro also and I found that it wasn’t very repeatable. I got more consistent results from my Shooting Chrony Beta. I also found that I needed to be sure that I was shooting thru the exact same spot on the Chrony or the readings would be off.
For serious regulator adjustments, I came up with this. I know that each shot string is going to go thru the same spot.
HOOT: here is the gauge that I got from McMaster Carr. It is rated 1.5% accurate for the full range. These types of gauges have the best accuracy at ½ of the max pressure. McMaster Carr has gauges that have .5% accuracy but, they cost big bucks!
I looked up gages on the Enet to compair prices. If you want a really accurate gage do what I di, go to the nearest Hydralic shop and buy it. They are 25% of the price you are paying for those PCP gages and their accuracy is on the money, I have used them for a life time setting pressure on continous Miners that go up to 4500 Psi, and as low as 125 psi, and the accuracy is critical on a Miner that goes on stroke on zero pressure. So if you are not using pure oxygen,,, and are using pcp guns and a pump like I do, then the hydralic gage is the best and you will still have enought money left to take the Misses out to lunch. 😀 😀 They even sell those 5000 pound hoses for 1/3’rd of the web price. The name PCP hose is expensive, just like a gun made in the UK compaired to it being made here, the grass is always greener on the other side LOLOL 😀